Screw-cutting machine



(No Model.) 4 Sheets--Sheet 1. W. TUCKER. SCREW CUTTING MACHINE.

No. 500,043. Patented June 20, 1893.

fzzxiemorx 3 172 1722212 VIZ THC/f8] A:

(No Model.) 4 Sheets-Sheet 2.

W. W. TUCKER. SGRBW CUTTING MACHINE.

No. 500,043. Patented June 20, 1893.

I fzzr ezzzorx William W Ta cker By/y/sflfiarzzeyM 2 4 SheetsSheet 4.

W. W. TUCKER.

SGREW CUTTING MACHINE.

No. 500,043. Patented June 20, 1893.

(No Model.)

lllllllllllfllllllhl 171211795565: fzzr ezzforx gm? gal 9 W/ZZ/Qm WTue/rem UNITED STATES PATENT OFFICE.

WILLIAM W. TUCKER, OF HARTFORD, CONNECTICUT.

ISQREW-CUTTING MACHINE.

SPECIFICATION forming part of Letters Patent No. 500,643, dated June 20,1893.

Application filed March 10, 1893.

To all whom itmay concern:

Be it known that I, W 1LLIAM W. TUCKER, a citizen of the United States,residing at Hartford, in the county of Hartford and Stat-e ofConnecticut, have invented certain new and useful Improvements inScrew-Cutting Machines, of which the following is a specification. I

This invention relates more especially to that class of screw-cuttingmachines in which the screw-cutting die is carried by a revolving turretmounted on a slide movable longitudinally of the axis of the piece to bethreaded;

the object being to furnish an improved die of the so-called self-opening class and means for automatically re-setting the die.

In the drawings accompanying and forming a part of this specification,Figure 1 is a plan view of a screw-cutting machine furnished with mypresent improvements. Fig. 2 is a front elevation of the machine andscrewcutting mechanism shown in Fig. 1. Fig. 3 is an enlarged frontelevation of the screwcutting die shown on a smaller scale in Figs. 1and 2. Fig. 4=is an end elevation of the screw cutting die as seen fromthe left hand in Fig. 3. Fig. 5 is a cross-sectional view in line a-a,Fig. 3. Fig. 6 is a vertical longitudinal section through the die shownin Figs. 3 and 4, showing the chaser-holders set in position ready foruse. Fig. 7 is a view similar to Fig. 6, showing thechaser-holderactuating Wedge retracted for opening the dies when the dieis to be quickly withdrawn from the threaded piece of work. Fig. 8 is atransverse sectional View in line cc, Fig. 3. Fig. 9 is a plan view ofthe forward end of the die-body, shown with the chaser-holders removedbut with the guard-springs in place. Fig. 10 is an end elevation of theparts shown in Fig. 9, as seen from the left hand in said figure.

Similar characters designate like parts in all the figures.

ing certain features "of my present improvements; which dies aredesignated in a general way, and respectively, by A and A said dies,however, are each of the same detail Serial No. 465,464- (No model.)

-H, which has at one end thereof the usual stem 3 whereby to support thedie in the turret of the screw-machine; and which has at the other endthereof the head or flange R wherein to support the chasercarriers. Saiddie-body is shown having a central bore, 4, (Figs. 4 to 10, inclusive,)for receiving the end of the piece being threaded, when thispiece is ofconsiderable length. For the purpose of receiving the severalchaser-carriers or holders, the head R of said die-body is shown havingformed therein the four radial slots designated in Fig. 10 by 5,6, 7 and8, respectively; in said slots are pivotally supported the correspondingseries of chaser-carriers or levers designated by 9,10, 11 andl2,respectively. Said'chaser-holders together with the details used inconnection therewith, being alike in construction and mode of operation,a detailed description of one'of them will suffice as a description ofthem all.

The chaser-holder 9, shown at the upper side of the view in the severalfigures of the drawings, is fitted closely between the sidewalls of theslot 5, and is pivotally supported in said slot by means of thepivot-pin 13, (Figs. 3, 6, 7 and 8,) which is usually a tapered pinfirmly driven into the shank-head R. The forward or projecting end (atthe left hand in Fig. 3), is constructed to carry the screw-cuttingchaser 17, Whose inner end is furnished with the usual cutting-teeth 21,and

which bears at its outer end against the head 25 of the adjusting-screw29, whereby the chaser may be adjusted radially of the die foraccurately setting the same. The preferred arrangement of the adjustingscrew 29 is best shown in Figs. 6 and 7, it being screwed into thethreaded outer end of the hole 33,

which below the point of the screw contains the lever-actuating spring37 whose inner end reacts against the bottom surface of the aforesaidslot 5. v

For holding the chaser in place on the chaser-holder, said chaser hasformed therein the slot 40, (Figs. 6 and 7) through which passes abinding-screw ll that is screwedinto the chaser-holder 9, as indicatedin the draw- -in position on the chaser-holder without throwing too muchstress upon said binding-screw 41, the chaser has formed therein theslot or groove 42, which fits over a corresponding tongue, 43, on thesaid chaser-carrying holder 9. This arrangement will be readilyunderstood by comparison of Figs. 3, 4, 6 and 7. By means of thisconstruction the principal strains upon the chaser laterally thereof, or

longitudinally of the die-shank, are taken by the tongue and groove, sothat the bindingscrew is subjected to but comparativelylittle strain.

For the purpose of preventing the collection of chips and dirt under thechaser-carrying levers 9, a guard-spring, 14, is fitted into thelever-slot in the head R of the die-body H, being held in place at therearward end of said slot by the screw 15, as will be under-I stood bycomparison of Figs. 6 to 10, inclusive. The forward end of saidguard-springisnbent at about a right angle, and the point thereof fitsclosely the forward or outward surface of the die-body, as illustratedin Figs. 6, 7 and 9; while the angle of said spring bearsoutwardlyagainst the innersurface of the chasercarrying lever 9. Nearthe forward end of the spring an opening, 39, is made in theguard-spring 14 for the passage of the aforesaid lever-actuating spring37, so that said actuating-spring may bear against the diebody asrequired for the proper operation of the lever. One'of saidguard-springs being fitted intoeach of the aforesaid slots, 5, 6, 7 andS of the die-head R, (see Fig. 10,) the tool is securely guarded againstthe entrance of chips between the chaser-levers and the central portionof said die-body.

The details used in connection with the chaser-holders 10, 11 and 12,are designated by the same characters with the additionof prime, secondand third marks, respectively, as are used in connectionwith thechaserholder 9.

As a means for setting the chaser-levers and their chasers in properposition for use, (as in Figs. 3, 4 and 6) a tubular wedge, 16, isfitted to slide closely but freely on th e. middle portion of thedie-body between the head R thereof and the stem whereby said die-bodyis supported in the turret E of the screwcutting machine. For actuatingsaid tubular wedge, this is shown provided with a stopcarryingclamp-ring, 18, which is adapted to be set on said wedge at suitablepoints longitudinally' thereof, by means of the set-screw 19operating ina well-known manner, see Figs. 3, 5, 6 and 7. Said stop-ring 18 in itslower projecting end 30 isbored longitudinally, of the die-body toreceive the stop-rod 20,

. which is held in place in said stop-ring and longitudinally of thedie-body by means of another set-screw, 22, shown :best in Figs. 3, 4and 5. .As a means for properly limiting the longitudinal movement ofsaid Wedge on the is properly limited, and they are prevented from beingthrown out too far by the springs 37 and 37". The lever-actuating spring37 beingcontained in the inner end of the leverperforation 33, (whichperforation, it will be seen, is alongside of the chaser 17,) actsbetween the screw 25 and the die-body for re tracting the chaser-lever.By this means, also, on removing said screw 25, said spring may beremoved and replaced without the necessity of removing the chaser-leverfrom the die-body. This feature permits the ready replacing of thesprings when any breakages thereof occur, and is otherwise convenient inkeeping the tool in proper repair. Also, by removing the screwand springas set forth, access is had through said perforation 33, and through theopening 39 in the guardspring 14, to the space inclosed between theguard=spring and die-body, so that any dirt accumulating in that spacemay be readily removed without disassembling the die.

In using the die, this is fixed by the stem 3 thereof in the turret, asE, of asnitable screw cutting machine; said turretbeing mounted upon theslide G, and this supported to move longitudinally of the-machine on theslideblock F. Since the same do not form. any part of my presentinvention and are also well known in the art, I haveomittedto show theusual means for operatingthe slide G or for spindle S of thelathe-headO; thishead being carried, as usual, upon the bed B ofthescrewcutting machine. 'Thesemachines are ordinarily furnished with across-slide block, M, carrying an ordinary cross-slide, L, which isusually fitted to have aconsiderable movement transverselyof thelathe-body B for carrying cutting-off tools not shown herein.

Underneath the workingposition of the screw-cutting die, I provide astop located in position for striking the aforesaid stop-rod20 of saiddie, and, through this and the saidstop-carrying clamp-ring 18,retracting the aforesaid tubular wedge from its position shown in Fig. 6to that shown in Fig. 7 at the moment of completing the screw-cuttingop: eration. As a matter of convenience, said stop-plate or abutment,which is herein designated by N is shown supportedon the slideblock M,and may ormaynot have a move cient that said stop-abutment shall bemaintained in proper position for always intercepting the forwardmovement of the stoprod 20 while the screw-cutting die is in use. Ifpreferred, obviously, the abutment N may be any suitable piece or blocksuitably supported on the bed 13. In practice, I prefer to fix saidabutment on the usual slide-block M when the machine is provided withsuch block, since this block is usually fitted to be adj ustablelongitudinally of the bed of the machine;

which adjustment is convenient for properly locating the abutmentitself.

In Figs. 1 and 2 the turret E is shown provided with two screw-cuttingtools, Aand A, of duplicate construction and set the one opposite to theother. The tool at the left hand is shown set ready for use the same asin Figs. 3, 4 and 6. In Fig. 2, the screw-cutting tool is shown, bydotted lines at A", advanced into engagement with the piece of work P,and with its stop-rod 20 striking against the face of the abutment Nready for retracting the tubular wedge 16 on the farther forwardmovement of the tool. This movement having been effected, the wedge isdrawn back to nearly the position shown in Fig. 7, so that the rearwardends 27 of the chaser holders 9 slide 01f from the outer surface 28 atthe point of said wedge, thereby allowing the chasers to open as shownin said figure. This operation having been effected, the slide G isdrawn back to its position in Figs. 1 and 2, making the machine readyfor the turning of the turret. This latter operation carries the dielast used around toward the back of the machine, (as indicated by thearrow on the turret E, Fig. 1) and brings the lower end 30 of saidclampring 18 in engagement with the cam-face 31 of the resetting cam 32;this cam is shown fixed on the slide G immediately rearward of theturret E, and operates to throw forward said tubular wedge, and tothereby reset the chaser-holders in their operative position shown'inFigs. 1, 2, 3, 4 and 6, ready for a repetition of the foregoingoperations.

Having thus described my invention, I claim 1. In a screw-cuttingmachine, the combinationwith the work-holding spindle, and the turretand its carrying slide, of the self-opening die carried in the turretand having a longitudinally-movable wedge for re-setting thechaser-holders of the die, the chaser-holders carried by said die, astop-abutment secured to the bed of the machine, a stop carried by thewedge with its abutting end outside the plane of movement of the work,and in position for engagement with said abutment on the forwardmovement of the die to retract the wedge and thereby permit the die toopen, substantially as described.

2. In a screw-cutting machine, the combination with the bed of themachine, the workh lding spindle, the turret and its slide, of

' the self-opening die carried in the turret and having the cylindricallongitudinal wedge, for

. and permit the opening of .re-setti'ng the chaser-holders of the die,the

stop-carrying ring adj ustably-secured to the wedge, the stop carried bysaid ring, and the abutment secured to the bed of the machine inposition to be engaged by the said stop in its forward movement, toretract the'wedge the die, substantially as described.

3. In a die of the class specified,'the combination with the die-body,and with the chaser-carrying lever pivotally supported in a slot thereinwith a space between the inner side of the lever and the die-body, ofthe guard-spring intermediate to said lever and die-body and having thebent forward end closing the forward end of the slot below the lever,substantially as described.

4:. In a die of the class specified, the combination with the die-bodyhaving a slotted head for receiving the chaser-carrying lever, and withmeans for actuating said lever, of the guard-spring closing the forwardend of the slot below said lever and having an opening therein, and aspring carried in the lever and projecting therefrom through saidguardspring opening against the die-body, substantially as described.

5. In a die of the class specified, the combination with the die-bodyhaving the slotted head for receiving the chasercarrying lever, of thelever 9 carrying the radially-adj ustable chaser 17 and having aperforation entirely through the same alongside of said chaser, thechaser-adjusting screw 25 fitting in the threaded outer end of saidlever perforation, and the spring in said perforation and acting betweensaid screw and thedie-body, whereby the spring may on removal of thescrew be removed and replaced without removing the lever from thediebody, substantially as described. a

6. In a die of the class specified, the combination with the die-bodyhaving a shank and a series of chaser-levers, of the wedge carried andfitted to slide on the shank, means for supporting the die in ascrew-cutting machine, a fixed abutment, as N, located beyond the pathof the die, and a stop carried by the wedge in position for engagingsaid abutment to retract the wedge on the shank of the die-body,substantially as described.

7. In a screw-cutting machine, the combination with the bed of themachine, the turret, its slide, the self-opening die and its operatingwedge, of a stop carried by said wedge, an abutment located upon the bedin position to be engaged by one end of the stop in the forward movementof the turret to re tract the wedge and allow the opening of the die,and a cam located upon the turret slide or support to engage theopposite side of the stop during the rotation of theturret to force thewedge outward and automatically re-set the die, substantially asdescribed.

8. In a screw-cutting machine, the selfopening die carried in theturret, and having the longitudinally movable wedge, the turret and itsslide, the stop carrying ring upon the wedge, the stop carried thereby,and the abutment to engage one side of the stop in its longitudinalmovement to press the wedge inward, 'a cam-abutment toengage the oppo-jsite side of the stop to press the wedge out-' Ward when the turret isrevolved, and an adjusting screwordevioe to adjustably secure thestop-ring'to the wedge, substantially as IO j described.

WILLIAM W. TUCKER.

Witnesses:

FRED. J. DOLE, FRANK E. TRACY.

